Recirculation filter for an enclosure

Abstract

The technology disclosed herein relates to filter assemblies and methods of making filter assemblies. One filter assembly has a first sheet of filter media having a first perimeter region and a second sheet of filter media having a second perimeter region. The first perimeter region and the second perimeter region are bonded in a rim region. A plurality of adsorbent beads are disposed between the first sheet of filter media and the second layer of filter media, and a substantial portion of the plurality of adsorbent beads are unbonded. Other embodiments are also described.

1 - 17 . (canceled) 
     
     
         18 . A method of making a filter assembly comprising:
 placing a first sheet of filter media between a first mating structure and a second mating structure, wherein the first mating structure defines a perimeter and a cavity recessed from the perimeter and the second mating structure defines a protrusion configured for mating engagement with the cavity;   compressing the first sheet of filter media between the first mating structure and the second mating structure such that the first sheet of filter media defines and retains a cavity structure and a rim region about the perimeter of the cavity;   creating a partial vacuum within the cavity of the first sheet of filter media;   disposing adsorbent beads within the cavity of the first sheet of filter media while the partial vacuum is within the cavity of the first sheet of filter media; and   coupling a perimeter region of a second sheet of filter media to the rim region to contain the adsorbent beads between the first sheet of filter media and the second sheet of filter media.   
     
     
         19 . The method of  claim 18 , wherein the first sheet of filter media comprises a first layer of filter media and a second layer of scrim material. 
     
     
         20 . The method of  claim 18 , wherein the adsorbent beads comprise activated carbon beads. 
     
     
         21 . The method of  claim 18 , wherein creating a partial vacuum within the cavity comprises:
 placing the first sheet of filter media on a vacuum station defining an airflow pathway from the cavity through the vacuum station; and   generating airflow from the cavity into the vacuum station.   
     
     
         22 . The method of  claim 18 , wherein coupling the second sheet of filter media to the rim region comprises welding the second sheet of filter media to the rim region of the first sheet of filter media. 
     
     
         23 . The method of  claim 18 , wherein the first sheet of filter media has a permeability of between about 250 ft./min. at 0.5 inches of water and about 750 ft./min. at 0.5 inches of water. 
     
     
         24 . The method of  claim 18 , wherein the adsorbent beads have an average size of 0.4 mm to 0.8 mm. 
     
     
         25 . The method of  claim 18 , further comprising increasing the rigidity of the rim region by melting the rim region of the first sheet of filter media and then cooling the rim region of the first sheet of filter media. 
     
     
         26 . The method of  claim 18 , wherein the first sheet of filter media and the second sheet of filter media are different materials. 
     
     
         27 . The method of  claim 18 , wherein the first sheet of filter media and the second sheet of filter media are the same materials. 
     
     
         28 . A method of making a filter assembly comprising:
 placing a first sheet of filter media over a die defining a perimeter and a cavity recessed from the perimeter;   creating a partial vacuum within the cavity of the die;   disposing adsorbent beads on the first sheet of filter media while there is the partial vacuum within the cavity; and   coupling a second sheet of filter media to the first sheet of filter media to contain the adsorbent beads between the first sheet of filter media and the second sheet of filter media.   
     
     
         29 . The method of  claim 28 , wherein the first sheet of filter media is substantially planar and creating a partial vacuum flexes the first sheet of filter media towards the cavity. 
     
     
         30 . The method of  claim 28 , wherein a substantial portion of the adsorbent beads are unbonded. 
     
     
         31 . The method of  claim 28 , wherein coupling the second sheet of filter media to the first sheet of filter media comprises melting the first sheet of filter media and the second sheet of filter media together in a rim region surrounding the adsorbent beads. 
     
     
         32 . The method of  claim 28 , wherein the coupling comprises melting the second sheet of filter media to the first sheet of filter media in the rim region. 
     
     
         33 . The method of  claim 28 , wherein the adsorbent beads comprise activated carbon beads. 
     
     
         34 . The method of  claim 28 , wherein creating a partial vacuum within the cavity comprises:
 generating airflow across the first sheet of filter media into the cavity.   
     
     
         35 . The method of  claim 28 , wherein the first sheet of filter media has a permeability of between about 250 ft./min. at 0.5 inches of water and about 750 ft./min. at 0.5 inches of water. 
     
     
         36 . The method of  claim 28 , wherein the first sheet of filter media and the second sheet of filter media are different materials. 
     
     
         37 . The method of  claim 28 , wherein the first sheet of filter media and the second sheet of filter media are the same materials. 
     
     
         38 - 49 . (canceled)